Reland "Specialize SkRectanzier to SkRectanizerSkyline"

This is a reland of 77e1f84a84a7d9dd4beae2e7c83ce63f00500cc2

Original change's description:
> Specialize SkRectanzier to SkRectanizerSkyline
> 
> It looks like the pow2 rectanizer has never been used. Remove
> the unneeded abstraction for rectanizer everywhere.
> 
> Change-Id: Iba33f1c6faf37201d03928ce8409751c212480a0
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/265983
> Commit-Queue: Herb Derby <herb@google.com>
> Reviewed-by: Mike Klein <mtklein@google.com>

Change-Id: I09729ba2b0e4b8b1a229fef4b95e65195b33fdc7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/266180
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
12 files changed